A switching drive of semiconductor switching elements behaves differently at the time of turn-on and turn-off that each need a different switching speed (hereinafter referred to as a SW speed). For example, radiation noise by recovery current and turn-on losses are problems during the turn-on. Meanwhile, overvoltage by surge voltage and turn-off losses are problems during the turn-off.
A technique for controlling charge and discharge current and controlling a SW speed by gate resistors having different resistance values located between each of a drive side and a sink side and a gate of a switching element has been used. In this case, the different resistors need to be located on the drive side and the sink side.
A configuration of a single ended push-pull (SEPP) circuit in which an NPN bipolar transistor and a PNP bipolar transistor are respectively located on a drive side and a sink side, and emitters of the transistors are connected to each other to output as one is often used as a buffer circuit, gate resistors being each located in the emitters of the SEPP circuit. This circuit has advantages in that a driving signal is rarely delayed due to the bipolar transistor having small input capacities, an emitter follower has low output impedance, and the circuit can easily be used at power supply voltage in a wide range without passing a flow-through current (see Patent Documents 1, 2, for example).